There are plenty of talking points about Sunday's game between the Green Bay Packers and the Detroit Lions but so far the most fascinating battle looks to be shaping up between Detroit's Calvin Johnson and the Packers Tramon Williams.

Williams is already talking some smack (via the Milwaukee Journal Sentinel) while Johnson is concentrating on trying to help his team salvage a season.

This chess match will be fascinating to watch.

The Lions will, of course, want to get the ball to Johnson as often as possible. However, they know the Packers will want their best guy—Williams—on Johnson all game.

How each team tries to counter the other's efforts will have a tremendous impact on this game.

Before we get into specifics on this game, let's look at the previous two meetings between these teams.

While the Packers won both games, they were only able to shut Johnson down once. In Week 12, they held him to just four catches for 49 yards, though Johnson did score a touchdown.

In Week 17, a huge shootout between the two teams, Johnson torched the Packers secondary for 11 catches, 244 yards and a touchdown.

Call that a split decision in 2011.

First, let's look at how Williams and the rest of the Packers secondary were able to limit Johnson's effectiveness in Week 12.

The first thing the Packers did was play Johnson very physical—jamming him on his routes and making contact with him as much as possible. Williams has already mentioned this as part of his game plan for Sunday, so you know the Packers liked how it looked to them when they watched the tape of this game, as well as film from this season.

The Lions didn't move Johnson around all that much.They didn't spread the ball around either, so Williams had ample opportunity to cover Johnson.

One thing which Williams did very well—and a potential key for his plan on Sunday—was jump Stafford's passes.

For a great example of this, check out this video from the game.

On the play, Williams (yellow circle) has Johnson (red circle) in man coverage, though he is playing off the big receiver as if to avoid Johnson running past him. The cushion isn't about not getting burned, though, it's about giving Williams a minute to read the route and Stafford.

As we punch in, Williams is sprinting forward but instead of mirroring Johnson, he jumps the route and nearly intercepts Stafford's pass.

The second angle on the video is an end-zone shot. It's pretty clear that Stafford had already decided to throw to Johnson. Whether Williams saw that as well and jumped the route accordingly is hard to say, but that explanation wouldn't shock me.

Stafford often forces the ball to his big-play wideout, and this could become an issue against Green Bay, especially given how inaccurate the Lions quarterback has been.

Between the single-minded efforts to get Johnson the ball and the physical play, it was a long day for Johnson, as well as the rest of the Lions offense.

It's not all sunshine and daffodils for the Packers, though, as Johnson has had their number multiple times over the years. It was especially true in Week 17 last year, when Johnson put up his enormous numbers on the defensive unit.

Now, to some extent you take the numbers with a grain of salt—this was a defense playing for nothing, with multiple players injured or resting for the upcoming playoffs. On the other hand, guys like Williams were playing and were responsible for getting blown up by Johnson.

Here, once again, Williams is paired against Johnson (red circle) and playing well off the line.

Unlike in Week 12, this time giving Johnson the cushion bites Williams in the rear end. Williams doesn't read the play quickly enough, and Johnson cuts his route short. Worse for the Packers, Johnson's route perfectly cuts between zones, and he's able to gain a ton of extra yards after the catch, as nobody is near enough to make a play.

So why did this work?

Well, first and foremost, the Lions were able to make some longer plays with Johnson earlier, making the threat of him going vertical on Williams very, very real.

On top of that, the other receivers do an excellent job of selling their shorter routes, pulling the coverage towards the line of scrimmage and away from the middle of the field where Johnson is going.

So how does this impact Sunday's matchup?

Well for the Lions, they will want to make sure they create room for Johnson to move and ways for him to get separation and open space after a catch. Of course, every once in a while Stafford will throw a jump ball, but for the most part, Detroit will want to take advantage of Johnson's strength and ability to break tackles after the catch.

Meanwhile, the Packers are going to want to slow his routes down and force Stafford into some tight throws, which in turn could generate turnovers.

The best-case scenario for the Lions is to keep Johnson away from Williams to begin with. In the Packers loss to the Colts back in Week 5, Indy WR Reggie Wayne tore them up, in part because the Colts moved him around constantly.

With the way the Packers' defensive scheme works, Williams isn't going to rove around looking for Johnson. He tends to focus on flankers and lines up on split ends only occasionally. Wayne was set up in the slot a ton and Williams isn't going to line up there often, if ever.

Now, Johnson isn't a slot receiver—or at least what we've come to see as a slot receiver. However, neither is Wayne and he did fine.

If lining up in the slot keeps him away from Williams, Johnson will have a better chance of success—especially since the most this secondary is awfully young. Casey Hayward and Devon House are still trying to get their feet wet, and if you ask for help from the safeties, you have equally inexperienced players in M.D. Jennings and Jerron McMillian.

Of course, you'll want to watch where safety Morgan Burnett lines up, but really, he's not a good enough cover guy to eliminate Johnson as a threat.

The Packers will then have to counter with some movement of their own. First, they might consider having Williams follow Johnson. Plenty of cover corners have locked onto a single receiver effectively, and Williams is good enough to shadow Johnson anywhere.

The danger in this is that it could give guys like Titus Young and Ryan Broyles more freedom to operate.

So an alternative is what Williams was talking about in the Journal-Sentinel article noted above. Play Johnson hard, hit him early and often (though cleanly) and when he gets his hands on the ball, make sure he knows you're there.

McMillian is a big hitter (as is Burnett), and if Johnson comes across the middle, having a linebacker like Erik Walden hammer him as he catches the ball will definitely leave an impression.

When the Vikings beat the Lions in Week 4, they effectively limited Johnson, and it had a ton to do with how physical they played him, so much so that he is still feeling the effects of it now (via mlive.com). He had a much better game against the Vikings this past week, though Minnesota was without Chris Cook, which made it much harder to contain Johnson.

It's clear that he's not 100 percent and having to take a beating could severely limit his effectiveness.

The Packers will likely pull in safety help regardless, and don't be shocked if they take a few shots at Johnson to rattle him early on.

Which then means that other Lions receivers, like the aforementioned Broyles and Young, need to make the Packers pay. The two young receivers have to start consistently punishing defenses when secondaries focus too much attention on Johnson.

Make the Packers respect the rest of the offense. So far this season the Lions receivers have been OK—this week they have to be better than OK.

Another thing the Lions can do to counter heavy focus on Johnson is to commit to the run. Mikel Leshoure and Joique Bell can find plenty of room to run against this defense. The Packers have allowed just one 100-yard running back this season (Frank Gore in Week 1) and nobody over 70 in the last three weeks, but during that stretch Green Bay saw some weak running games and established big enough leads that opposing offenses were forced to abandon the run.

Also, the Packers defense has struggled to contain the passing game as well, so why run when you can pass effectively. It's a vicious circle.

Green Bay's defense can be worn down if you commit to the run. Leshoure and Bell are a solid combo and can grind it out. If the Lions backs get going, the Packers will have to maneuver defenders to support whatever section isn't stepping up—which will leave more room for Johnson.

This is why they may want to spare Williams from covering other receivers and have him shadow Johnson more frequently.

There are a lot of permutations to this, which is what is so fascinating. Lions offensive coordinator Scott Linehan and Packers defensive coordinator Dom Capers will have to move their pieces around the field in a constantly shifting landscape.

The guy who finds the answer first could well have the game in his hands.